Unable to use Escape key to close Modal Frame after an inner Modal Frame has been closed

Steps to reproduce:

1) Open a Modal Frame, for example one attached to a "Create and reference" button.
2) From the child window, open a new Modal Frame attached to any node reference field and close it.

Now, that we're back on the first Modal Frame, pressing Escape key does not close that Modal Frame.

The problem is that closing the inner Modal Frame unbinds all the events of the first one, and this happens because these events are attached using the same jQuery namespace for events. The solution is to use a different namespace for each Modal Frame. Tricky.

Patch coming...